#!/usr/bin/ruby -w

TARGET_FREQ = ARGV.shift.to_f
NATIVE_FREQ = 50.0

CLOCK_WIDTH = 5

best = nil
best_mult = nil
best_div = nil
1.upto(2**CLOCK_WIDTH) do | mult |
  1.upto(2**CLOCK_WIDTH) do | div |
    new = NATIVE_FREQ * mult / div
    if not best or (new - TARGET_FREQ).abs < (best - TARGET_FREQ).abs or ((new - TARGET_FREQ).abs == (best - TARGET_FREQ).abs and (mult + div) < (best_mult + best_div))
      best = new
      best_mult = mult
      best_div = div
    end
  end
end

error = (best - TARGET_FREQ).abs / TARGET_FREQ
$stdout.write("Closest I can get is #{best}: *#{best_mult} /#{best_div} (#{(error * 100).round}% error)\n")